arm64: dts: imx8mq: Add SDMA nodes

SDMA1 is part of AIPS-3 region and SDMA2 is part
of AIPS-1 region.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>